Nov 7 (Reuters) - State-owned China Petrochemical Corp or Sinopec Group said on Monday it has completed its acquisition of an 80 perent stake in Pecten Cameroon Co from Royal Dutch Shell , gaining its first oil production assets in the African country.

Addax Petroleum, a unit Sinopec Group bought in 2009, inked the $538 million deal with Shell Overseas Holdings Ltd On May 25 for the stake in Pecten Cameroon Co, which owns interests in 12 blocks in waters off Cameroon.

Pecten Cameroon Co, 20 percent owned by Cameroon's National Hydrocarbons Corp (SNH), is the operator of two of the blocks.

Sinopec Group, the second-largest Chinese oil producer, said it will get 11,900 barrels of equity oil output per day or 600,000 tonnes a year from the joint venture in 2011.

Sinopec Group, also the top oil refiner in Asia, runs most of its businesses via listed China Petroleum and Chemical Corp or Sinopec Corp .